Neuromuscular diseases in cats manifest in three areas of the cats' bodies: the nerves and nerve roots, the muscles, and the junctions of nerves and muscles. Some feline neuromuscular diseases are genetically inherited while some are acquired through adverse reactions to certain medications or bacterial infections. Most exhibit distinct symptoms in the animal's movements and behavior, and a full neurological exam that includes blood work, urinalysis and abdominal ultrasound is necessary to produce a conclusive diagnosis. A veterinary neurologist may need to diagnose more difficult cases.
Neuropathies or Diseases Affecting the Nerves
This group of diseases develops in a cat's nervous system and involves the peripheral nerves and nerve roots. For example, ischemic neuromyopathy is seen in cats with heart problems following a malfunction in the aorta. Diagnosing neuropathies requires an observation of the area of the animal's body that is affected. Signs to look for include weakness, loss of balance, sensitivity to pain and confusion. Diabetic neuropathy is the result of nerve damage in diabetic cats. Symptoms include weakness in the hind legs, loss of balance and stopping often to lie down. Cats can also develop malignant lymphomas, or lymphatic cancers, that can involve peripheral nerves and nerve roots.
Myopathies or Diseases Affecting Muscles
Myopathies target the cat's muscles and can severely restrict its movements. Cats can inherit the gene for muscular dystrophy, and this disease occurs most often in males. Signs include excessive drooling, low tolerance to exercise, joint stiffness, vomiting and partial tongue protrusion. With potassium-depletion polymyopathy, a severe lack of potassium in the diet can cause muscle weakness, tenderness in the affected area, difficulty breathing and stiffness when walking. Infectious polymyositis develops as a result of a parasitic invasion or a bacterial infection and causes imbalance and confusion, as if the cat can't remember which leg to move next to take a step.
Junctionopathies or Diseases Affecting Nerves and Muscles
Junctionopathies encompass diseases originating in the connection between nerves and muscles and occur in cats as a result of tick bites, adverse reactions to certain drugs and the ingestion of toxic substances. Myasthenia gravis, the result of damaged receptors between the muscles and nerves, can be either inherited or acquired, the latter most often occurring in purebred Abyssinian and Somali cats. Symptoms may include tremors, muscle stiffness, difficulty breathing and facial weakness. Some cats may also vomit, drool, or have trouble swallowing and may also exhibit cervical ventroflexion, where the head drops down to the chest and cannot be raised.